This application claims priority under 35 U.S.C. xc2xa7119(a) to Korean Utility Model Application No. 2603/2001, filed in Korea on Feb. 3, 2001.
The present invention is directed to a disposable safety syringe constructed so that an attached needle may be disposed of safely and separately after use, additionally configured so that all fluid is forced from the barrel of the syringe, and further constructed so that the plunger may not be fully removed from the barrel, preventing inadvertent loss of fluid that has been drawn into the syringe barrel.
A conventional disposable syringe is constructed such that fluid to be injected is forced out of the barrel of the syringe when pressure is exerted on the syringe plunger. The barrel of a conventional syringe typically tapers at one end to accommodate the base of a needle.
When the plunger is forced into the barrel, the end of the plunger cannot fully enter this tapered portion of the barrel. Thus, a small amount of the injection fluid is left unaffected by pressure exerted by the plunger, and remains in the tapered portion of the barrel. Although this remaining amount of fluid (e.g. 0.07 cc) may seem negligible, repeated waste of this small quantity leads to economic loss.
A conventional syringe also lacks a mechanism to prevent one from pulling the plunger completely out of the barrel. If one mistakenly removes the plunger while drawing fluid into the barrel, the fluid can be lost.
Conventional disposable needles are typically covered by a cap for protection. This cap is removed before use, and replaced prior to needle disposal. If this conventional needle cap inadvertently falls off, individuals handling the needle, such as health care professionals and sanitation workers, may be pricked by the exposed needle, potentially exposing themselves to blood borne diseases.
The present invention remedies the aforementioned problems by incorporating several novel features. First, a plunger tip of new design allows all fluid to be forced from the tapered portion of the syringe barrel into the needle. Second, a slanted protrusion on the interior of the barrel prevents a user form inadvertently pulling the plunger fully out of the barrel. Third, after an injection is given, a newly designed protective needle shield can be moved and locked into position, shielding the needle from touch. A disposal cap may then be placed on the top of this shield. The movement of this shield into position also allows dislocation of the protected shield and needle from the syringe, allowing for separate needle disposal.